Transport of moisture at epoxy–SiO2 interfaces investigated by molecular modeling

In this work, the transport of water molecules at the interface of an epoxy molding compound to a SiO2 (chip surface) is investigated by molecular modelling. Experi-mental results of bulk diffusion of H2O into a DGGOA/DAIIBA epoxy/hardener system at several temperatures are compared to molecular dynamics results at elevated (artificial) temperatures with respect to activation energies. Molecular modelling allows to trace individual molecules over time. The recorded traces are evaluated in a semi-quantitative way with respect to jump-distances and comparisons are made between bulk diffusion, diffusion at an interface and diffusion at open surfaces of the involved materials. Results show reasonably agreeing activation energies in experiment and simulation and an enhanced transport at open surfaces. A significantly enhanced transport at a perfect interface could not be confirmed in this investigation.